V.V.V.V.V.
Houses Ov Mercury
It sure sounded like your point was that "bands are getting bassier" and also that "No one is trying to sound like Nattens Madrigal anymore" which really sounds to me like you just want BM bands to conform to your idea that raw = treble. Bass is being emphasized in BM because there's a stylistic evolution that seems to be leading bands to believe (sometimes correctly) that bass is a relevant instrument in the music. I am confused, primarily, about why you brought up Mgła, because, once again, I am asserting that he utilizes some very important bass tones that necessitate the focus on that aspect of the production. Black metal is primarily about being focused on atmosphere and momentum of music rather than "rhythm" and the logical extension that rhythm affects riff structure, as it does in most death metal that exists. I think that the bands who utilize these "bass-heavy" tones are merely succumbing to a necessary progression in the timeline of black metal that seems to dictate what is okay for bands to do while still remaining, at their core, black metal (that is, while not becoming "death metal").